A stent is a medical device introduced to a body lumen and is well known in the art. Typically, a stent is implanted in a blood vessel at the site of a stenosis or aneurysm endoluminally, i.e. by so-called “minimally invasive techniques” in which the stent in a radially reduced configuration, optionally restrained in a radially compressed configuration by a sheath and/or catheter, is delivered by a stent delivery system or “introducer” to the site where it is required. The introducer can enter the body from an access location outside the body, such as through the patient's skin, or by a “cut down” technique in which the entry vessel is exposed by minor surgical means.
Stents and similar devices such as stent-grafts, expandable frameworks, and similar implantable medical devices, are radially expandable endoprostheses which are typically intravascular implants capable of being implanted transluminally and enlarged radially after being introduced percutaneously. Stents can be implanted in a variety of body lumens or vessels such as within the vascular system, urinary tracts, bile ducts, fallopian tubes, coronary vessels, secondary vessels, etc. Stents can be used to reinforce body vessels and to prevent restenosis following angioplasty in the vascular system. They can be self-expanding, expanded by an internal radial force, such as when mounted on a balloon, or a combination of self-expanding and balloon expandable (hybrid expandable).
Stent protectors are used to protect the stent before the stent and catheter assembly are implanted into a body lumen. The stent protectors protect the stent from physical damage or contamination due to the transfer of unwanted material and are removed at the time of use to permit deployment of the stent. Examples of stent protectors are provided in U.S. Pat. No. 6,152,944 and U.S. Pat. No. 6,783,542.
Stent protectors have relied on a friction fit between the stent and the stent protector in order to hold the protector in place. However such intimate contact may not always be desirable. Stents are often used as a vehicle for delivering therapeutic agents (e.g. in the form of a coating on the stent). When removing the stent protector the friction fit could result in therapeutic agent being scraped off. In addition material from the stent protector can also be deposited onto the stent.
Without limiting the scope of the invention a brief summary of some of the claimed embodiments of the invention is set forth below. Additional details of the summarized embodiments of the invention and/or additional embodiments of the invention can be found in the Detailed Description of the Invention below.